1. Field of the Invention
The present invention relates to a laser device, particularly to a laser device for surgery.
2. Description of Prior Art
As is widely known, conventional surgical laser devices are generally classifiable as one of two kinds of systems, namely:
(A) a system (hereinafter called System A) in accordance with which a laser beam oscillation device is secured to and extends horizontally on the system housing, and laser beam transmission devices such as a multiply manipulator which includes multiply articulated mirrors to lead the laser beam, flexible wave guide, optical fiber and the like are fixed to an opening in the device through which the laser beam is emitted; and
(B) another system (hereinafter called System B) in accordance with which a laser beam oscillation control device and the laser beam oscillation device are arranged in a housing, and a laser beam transmission device such as the above mentioned multiply manipulator, flexible wave guide, optical fibers and the like are fixed to an opening in the housing through which the laser beam is emitted.
In case of the above System A, even if the total length of the laser beam oscillation device for producing a laser beam output (50-100 W) necessary for a surgical laser device is cut short by adopting a folded construction for the resonator, it is generally as long as about 1.5 m. Further, the area of the floor to be occupied with the housing containing the laser beam oscillation control device necessary for obtaining the above laser beam output is generally as large as about 80 cm.times.100 cm.
When an operation is carried out with a surgical laser device having the construction and the dimensions as mentioned above in accordance with System A, the housing and the laser beam oscillation device have little effect on the working area of the surgeon. However, considering the fact that the floor area of the operating room is generally as large as 6 m.times.6 m, the space of the operating room occupied by the surgical laser device is so large that the working area for attendants such as assistant doctors, nurses and the like is largely restricted.
Further, in case of the surgical laser device in accordance with System A, the above laser beam oscillation device is firmly secured above the housing, so that the position of the center of gravity is high. The optical system consisting of the above laser beam oscillation device and the above laser bean transmission device is thus often brought out of alignment due to shocks or vibrations during transportation of the system, resulting in undersirable changes of the laser beam output.
Further, in case of the device in accordance with System A, the horizontally arranged laser beam oscillation device is supported by means of a single vertical shaft at the center, so that the moment due to the weight of the laser beam oscillation device works upon both ends vertically downward. Thus, the support stand holding the laser beam oscillation device is distorted so as to accelerate warping of the optical alignment. Further, it goes without saying that the large space occupied with the surgical laser device in accordance with System A and its arrangement make transportation of the device all the more difficult.
In accordance with the System B, in the housing containing the laser beam oscillation control device, the laser beam oscillation device is vertically arranged. The laser beam emitted out of the laser beam emitting opening at the upper end of the laser beam oscillation device is transmitted up to an end piece connected to an end member of the laser beam transmission device such as a multiply manipulator secured to the ceiling directly above the laser beam emitting opening.
The construction of the surgical laser device in accordance with the System B is characterized in that the whole laser beam oscillation device including a discharge tube is vertically arranged in the housing, and that the laser beam transmission device is mechanically and firmly connected to the top of the above housing. Consequently, the height of the housing is about 2 m, and the total height including the laser beam transmission device projecting above the housing is 2.3 m-2.5 m.
Further, in the surgical laser device in accordance with the System B, the laser beam oscillation device and the laser beam transmission device are arranged separately from each other. Thus, due to thermal distortion, aging and mechanical deformation of the housing or the shocks, and vibration and the like during transportation, the optical axis of the laser beam oscillation device often goes out of coincidence with that of the laser beam transmission device. This lowers the laser beam output, which is undesirable. Further, as mentioned above, the surgical laser device is so high that transportation of the device often becomes impossible, the door lintel of the operating room becoming an obstacle.
As is widely known, generally it is necessary that communication among the doctor, the assistant doctors and the nurses should be carried out smoothly at the time of an operation. It is therefore believed that the height of the appliances equipped in the operating room should be limited to a height at least lower than the human eye, preferably 1 m.
Taking the above into consideration, the device in accordance with the System B, whose housing is as high as or higher than 2 m, serves to hinder communication among the persons participating in the operation, which is not practical.
In the case of a CO.sub.2 laser device, which is generally used as a surgical laser device at present, the above mentioned manipulator is often used as a laser beam transmission device. In this case the necessary accuracy of the mirror to be used is remarkably high, so much so that it often occurs that the optical alignment is warped even from a slight shock, so as to lower the output extremely. Consequently, until now transportation of the surgical laser device after it has been once installed, is considered to be undesirable.
However, because more than one hour is generally needed for preparation for typical operations, it is desired that the appliances be movable from one to another operating room, in order to improve the efficient utilization of the appliances. Particularly for an appliance such as a surgical laser device whose field of application is very wide (for example, ordinary surgery, cranial surgery, plastic surgery, gynecological surgery, ophthalmic surgery and so on) and which is quite expensive, transportability is highly demanded.
The present invention is intended to offer a laser device, particularly a surgical laser device which can be realized in compact form so as to increase its portability, whereby the shortcomings of the conventional device as mentioned above are eliminated.